diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index a713d6e3bd030e..206cf6ee09d244 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -158,7 +158,7 @@ unsigned ConstantArrayType::getNumAddressingBits(const ASTContext &Context,
   if ((ElementSize >> 32) == 0 && NumElements.getBitWidth() <= 64 &&
       (NumElements.getZExtValue() >> 32) == 0) {
     uint64_t TotalSize = NumElements.getZExtValue() * ElementSize;
-    return 64 - llvm::countLeadingZeros(TotalSize);
+    return llvm::bit_width(TotalSize);
   }
 
   // Otherwise, use APSInt to handle arbitrary sized values.